1. Field of the Invention
The present invention relates to a molding nozzle device for producing hollow cylindrical snack foods, and more particularly to such a molding nozzle device designed to be mounted to free end of an extruder, which is used in making snack foods from doughs mainly composed of different kinds of pulverized grain, flavorings and the like.
2. Description of Related Art
U.S. Pat. Nos. 3,077,406 and 3,480,445 show methods and apparatuses for making puffed, hollow cylindrical snack foods having two or less percent water content. The method of making star-shaped cereal products according to U.S. Pat. No. 3,077,406 uses an extrusion type nozzle having three support rods to fix an elongated pin at its center, for extruding a cereal dough into a hollow shape whereas the method of making ready-to-eat food products according to U.S. Pat. No. 3,480,445 uses a single-axle extruder having an elongated pin extending from its screw axle to the outside, for extruding a dough into a hollow shape.
When hollow cylindrical ready-to-eat products are loaded with fatty confectionery material such as fatty vanilla cream or fluid chocolate, an injection syringe is used, and then if the circular holes of such hollow cylindrical ready-to-eat products are deformed, or if such cylindrical walls have irregular thickness, the syringe is liable to be caught inside to break or damage the cylindrical walls, thereby causing the leakage of fatty vanilla cream or fluid chocolate from the hollow cylinders. As a consequence production of such cereal or snack foods remains at a reduced efficiency because of relatively large amount of rejected food products.
As for the method of making star-shaped cereal products according to U.S. Pat. No. 3,077,406 the three support rods to fix the pin prevent the dough to flow at even rate in the nozzle, extruding the dough into a triangular-sectioned hollow body. The triangular-section thus formed makes it difficult to insert a cylindrical syringe, often causing the breaking or damaging of such hollow products.
As for the method of making ready-to-eat food products according to U.S. Pat. No. 3,480,445 a single-axle extruder has an elongated pin extending from its screw axle, and if the screw axle should rotate eccentrically, hollow products cannot have even circumferential thickness.